Hammer mfo



H. w. DENHARD..

ELECTRIC HEATER. APPLICATION FILED OCT. 31. 1911.

- 1 ,194,343 Patented Aug. 8, 1916.

2 SHEETSSHEET I.

H. W. DENHARD.

ELECTRIC HEATER.

APPLICATION FILED OCT. 3!, 1911.

1,194,343, v Patented Aug. 8,1916.

2 SHEETS-SHEET 2. 5 41 fiWfi-rzlar I Jfar 1 W 2127272077455.

UNITED STATES PATENT OFFICE. f

' HARRY W. DENHABD, OF SAN FRANCISCO, CALIFORNIA, ASSIGNOR TO THECUTLER- HAMMER MFG. CO., 01 MILWAUKEE, WISCONSIN, A CORPORATION OFWISCONSIN.

ELECTRIC HEATER.

Application filed Octoiiei'S To all whom it may concern:

-Be it known that I, HARRY Dnnrninh, a citizen of the United States,residing at ing, forming a part of this specification.

his invention relates to electric heaters.

' It relates particularly to electric heaters adapted for use aselectric toasters.

One of the objects of the invention is to provide an improved electricheater.

Another object is to provide an electric heater havin improved means forsupporting the heating units.

Another object is to provide an improved electric heater which willefficiently radiate the heat developed to the objects to be heated.

Other objects'and advantages of the invention will hereinafter appear.

The accompanying drawings illustrate an embodiment of the invention.

The views in the drawings are as follows:

Figure 1 shows a side elevation of a complete heater. Fig. 2 shows anend elevation of the "same with one of the doors open. Fig. 3 shows aside elevation of the heating unit with the casing in section. Fig. 4shows an end elevation of the connections for the unit and the doormechanism, a portion of the casing being removed. Fig. 5 shows a centralsectional view on line 5-5 of Fig. 3.

The heater illustrated herein is particularly adapted to be used as .anelectric toaster, the heating units being supported between verticallyextending side members of a substantially U-shaped frame 1 on a base 2,and including a. plurality of transversely extending heating coil's 3wound.

upon insulating tubes 4 having their ends supported in verticallyextending terminal inclosing members 5 of a substantially rectangularcross-section which are snugly fitted against the inner surfaces of theside members 1. The coils 3 may, if desired, be formed of va continuouslength of high resistance wire, or may be formed of a plurality oflengths of the same. In the con struction shown in the drawings, I haveillustrated a plurality of coils. The ends of these coils a e bro g t ateach en Specification Letters ratent. Patented Aug, 1916.

911. Serial N6i*6 5 7,807. I

ings are made by striking up suitable portions 7 andsuitableperforations are formed 1n these struck up portions arranged to rethrough suitable openings 6in the -inclosing members 5. In a preferredform these openaoY ceive the ends of wires or rods 8 which pass throughthe-tubular insulating memhers 4.- and have their ends overturned uponthe pro ect1ons 7 'as shown in F igs 3.and 4. As illustrated in thesefigures, the

adjacent. openings '6 are'ap-roiiadevd struck. up portlons 7 which era etoward f each other.

The resistance wire wound abou fl, is brought out through suitablensulatmg sheets 9, to conducting plates preferably carrying upon theirouter surfaces e tubes I binding screws 11 to which the ends of-the adaCent 0011s are attached. In this manner a continuous circuit is formedfrom one of the terminals 12 of the device, through the heating elementand back to the opposite terminal 12. The terminals 12 are preferablyfixed in suitable openings in the end of the base 2 as shown in Fig.3'and are suitably insulated therefrom, the ends of the conductorsleading to the heating coils passing upward from the inner ends of thesame through suitable insulating tubes 13.

As illustrated in Fig. 3, the lower ends of the members 5 arepreferably'bent over as at-M and then upward to provide extensions 15 towhich the side members 1 may be fixed by suitable screws 16. The upperends of the members 5 may also be provided with a bent in portion 17attached to the upper part of the frame. 'The conductor leading from oneof the terminals 12 is led directly to the first heating unit. Theconductor from the other terminal extends upwardly along the end member5 and between the same and the frame 1. The .conductor is suitablyinsulated from the casing by one or more sections of tubular insulatingmaterial 18.

In order that the heat may not pass upward from the heating coils tooreadily so that a proper amount of heat will be given to the articles tobe heated, I preferably provide each of the heating coils with a hood oreffectually prevent any contact with the.

heating wire.

As illustrated in Figs. 3 and 5, the members 1 are connected by atransversely extending bottom member 21. This member is provided withstuds 22 on its ends which pass through openings in the lower ends ofthe members 5 and serve to position the member 21. The member 21 is alsoprovided with one or more transverse extensions 23, and intermediatethese extensions is provided with smaller studs 24 arranged to receivethe lower ends of the grid rods 25, the upper ends of which are fixed inthe frame 1. As shown in Fig. 5 the extensions 23 project on oppositesides of the member 21 in a plane substantially parallel with the baseso that they serve to prevent articles held against the grid fromsliding down into contact with the base.

The base member 2 is preferably provided with brackets 26, having ears27 in which are journaled suitable doors 28. The brackets 26 arepreferably provided with extensions 29 secured to the top of the base bymeans of screws 30. The doors 28 are preferably so constructed as tosnugly inclose the heating unit, as shown in Figs. 1 and 2. In apreferred form they are provided with side flaps 31 which pass alongeach side of the end members 1 and are limited in their forward movementby suitable pins 32.

In order that the doors may be readily operated, they are provided witha spring mechanism. This mechanism is preferably carried upon the insideof the base 2, be neath the heating element, and preferably consists ofa single spring member 33 having one or more spiral turns 34 near itsopposite ends, and upwardly extending free ends 35.,

passing through openings or perforations 36 in the bottom of the doors,and bent over as at 37 within the ends of the same. When it is desiredto close the doors, all that is necessary to do is to start the door inits movement whereupon the spring completes the movement of the same.Further, the spring tends to hold the doors snugly closed,

and thus prevents accidental opening of the same. In a preferred formthe doors are also provided with a chamber 38 formed between the innerand outer walls which serves to cut down the heat losses at the side ofthe heater. It is of course obvious that the doors may be provided withany suitable may be provided upon a top plate 41 carried by the frame 1,so that the heater may be readily moved from sired. It is also ObVlOIlSthat the base 2 may be suitably insulated as by mounting the same uponsuitable feet 42, preferably provided with insulating pads 43.

By my improved construction I have provided a heater of increasedefiiciency wherein the heat developed by the passage of current throughthe heating coils is radiated to the objects to be heated. Such a deviceis particularly adapted to use in connection with electric heaters ofthe type known as electric toasters, broilers or the like. The losses ofheat by the upward radiation of the same and its conduction to theinclosing casing are effectually prevented by my im proved construction.By my improved arrangement of doors, I have been able to provide a doormechanism which may be readily operated and is extremely convenient inuse. Further, by the arrangement of the heat insulating chamber betweenthe walls of the door, I have materially cut down the heat loss byradiation from the doors, and have thus more effectually concentratedthe heat around the objects to be heated.

By my improved construction and ar rangement I am able to provide anexceedingly large surface of resistance material and utilize practicallythis entire surface in heating the articles. Further, by my improvedmanner of mounting and insulating the resistance material, I haveeffectually done away with any danger of short-circuiting or the like.and have provided a device which is well adapted to be heated to hightemperature. Further, by the improved mechanical construction of theframe and the supports for the heating coils, I have provided a devicewhich is very rugged and well adapted to withstand long use in servme.

While I have in this application described for purposes of illustrationone form which my invention may assume in practice, my invention iscapable of assuming other forms and I consequently do not wish to belimited to this particular form, but wish rather to include all thoseforms and adaptations of my invention falling within its spirit.

What I claim as new and desire to secure by Letters Patent is 1. Anelectric heater having a plurality of horizontally disposed heatradiating units arranged in substantially the same vertical plane, asupporting frame therefor having struck-up portions to which said unitsare attached, and hoods above each of said units to reduce the heat lossin an upward direction.

2. An electric heater having a plurality of heating units arranged insubstantially the same plane comprising insulated rods wound place toplace as dewith resistance material, a supporting frame therefor havingstruck-up portions to which said heating units are attached, saidresistance material having its ends extending through the openingsformed by said struck up portions, and binder plates located betweensaid struck-up portions and insulated from said frame whereby said unitsmay be connected together electrically.

3. An electric heater having a plurality ofhorizontally disposed heatingunits arranged in substantially the same plane, a supporting frametherefor having struckup portions to which said units are attached,insulating strips between certain of said struck-up portions, and binderplates on said insulating strips whereby the heating units may beelectrically connected.

-l. An electric heater comprising a plurality of heat radiating unitsarranged in substantially the same plane, a supporting frametherefor,'guards on opposite sides of said heating units arrangedsubstantially at right angles thereto for confining the heat to theinclosure thus formed and a hood for each of said units to reduce theheat loss in an upwardly direction.

5. An electric heater having a plurality of heating units, a supportingframe therefor having struck-up portions to which said units areattached, said struck-up portions being formed so that openings areprovided in the frame through which the ends of the resistance materialof the heating units may pass to the outside of the frame.

(3. An electric heater having a plurality of heating units, a supportingframe therefor having struck-up portions to which said units areattached, said struck-up portions being formed so that openings areprovided in the frame through which the ends of the resistance materialof the heating units may pass to the outside of the frame, and insulatedmeans on the outside of said frame adjacent the struck-up portions towhich means the resistance material is electrically connected wherebythe heating units are connected together.

7. An electric heater having a plurality of heater units arranged insubstantially the same plane, a supporting frame therefor having itsends and bottom arranged to confine the heat adjacent the heating units,hoods above each of the unitsto reduce the heat loss in an upwarddirection, and heat insulated doors adapted to cover the sides of theframe.

8. An electric heater having a supporting frame carrying a plurality ofheater units arranged in substantially the same vertical plane, hoodsabove each of said units for reducing the heat loss in an upward direc--doors having spaced walls to reduce heat loss at the sides of the heaterunits.

10. An electric toaster comprising a frame having vertical end membersprovided with struck-up portions, heater units carried by said struck-upportions, said portions being formed so that openings are provided inthe end members through which the resistance material of the heaterunits may pass to the outside of said members, insulated binderplates onthe outside of said frame adjacent said openings to which plates theresistance material of the heater units is electrically connectedwhereby the units may be conneced together, and electric terminalsconnected to certain of said binder-plates.

v 11. An electric toaster comprising a frame having vertical end membersprovided with struck-up portions, heater units carried by said struck-upportions, said portions being formed so that openings are provided inthe end members through which the resistance material of the heaterunits may pass to the outside of said members, hoods above each of saidunits to reduce heat loss in an upward direction, said end members beingadapted to prevent heat loss at the ends of the units, rods adjacent thesides of the units against which the material to be toast-.

ed may bear, and pivoted doors adapted to hold the material to betoasted against said rods, saiddoors having spaced walls to reduce heatloss in a horizontal direction.

In witness whereof, I have hereunto subscribed my name in the presenceof two witnesses.

HARRY W. DENHARD.

Witnesses:

S. L. COGKRELL, GEO. B. Jones.

